There has been an aura of uncertainty attached to metals identification by electrical interpretation. This has been due in a large sense to limited test capability regarding range of materials and lack of information about troublesome responses from side effect variables. After thorough testing of a new apparatus, it is now believed that a new plateau of development has been attained. In more than a year of production line service, the equipment has shown high reliability for continuous identification by comparison. It enables quick detection of product variation and eliminates hours of costly delay and loss of material. It has proved useful as a laboratory method of identification of unknowns when the unknowns are brought to a common state to minimize variables.